Large area image sensors (e.g., 8″ by 8″, 16″ by 16″) have various applications including x-ray applications, mammogram applications, medical applications, and for electron microscope applications. Typically, an x-ray imager may comprise a CMOS (Complementary Metal Oxide Semiconductor) image sensor and a scintillator. The scintillator converts x-rays to visible light, which impinges a photodiode in the image sensor. The image sensor also includes control logic and a readout circuit for reading a pixel of image information from the photodiode. A typical image sensor has photodiodes that form pixel arrays, control logic, and readout circuits to generate an entire image. The image may be displayed on a monitor or printed for viewing purposes.
Typically in large area sensors for x-ray applications, the control logic includes multiple shift registers in the y-direction of the image sensor. These registers are embedded in the pixel arrays to allow side butting of dies each having one or more sensor arrays. Physically separated dies are assembled together to create a large format image sensor. If a single shift register is corrupted with a faulty value, this affects the entire image sensor, which is then corrupt as well.